Linda and Roger's Bunhybee Grasslands - Grazing


This is a page within Roger and Linda's Bunhybee Grasslands Web-Site.

Bunhybee Grasslands is a 49 hectare / 120 acre conservation property 35km south of Braidwood, in southern N.S.W.

You can follow through the internal links, or you may find it easier to use the Site-Map.


Background

This page contains information about the grazing strategy for the property.

The strategy reflects our current understanding of the property's history.

It seems incongruous that a native grassland that is subject to a Conservation Agreement should be grazed at all. The reasons for conducting grazing appear to be that:

On the other hand, reasons to not graze, or minimise grazing, include:

The following sections present the following information:


The State of Knowledge at the Date of Purchase

This is summarised in the Plan of Management, from which the following quotations are taken. Most of the emphases have been added. Those in the original are noted accordingly.

"'The Parlour Paddock' has a long history of grazing by sheep and more recently cattle. The two large paddocks were historically set stocked by sheep at low rates, predominately due to the paucity of water in the paddocks. There is no history of cultivation and fertilizer was only applied once to the Jerrabatgulla valley paddock (Pers. Comm. David O’Connell Dec 2007). There is evidence of clearing across “The Parlour Paddock” particularly of the Snow Gum Woodland community occurring on the lower slopes. The area has been burnt at some time in recent decades, with fire scars present on trees in the forested slopes of Bunhybee Hill" (Plan of Management p. 5).

NCT's Nigel Jones advised on 18 Feb 09 that "Previous to the famous 9 (10?) whilst the property was for sale [i.e. during 2007?], there was black cattle grazing for around 7 months ... not sure of numbers but safe to say 30-40 across - both properties [presumably 2005-06?] ... Unfortunately a bit of pugging occurred during Spring ...". We think 'pugging' means (highly undesirable) soil compaction arising from grazing on wet soil and grass.

Grazing Management is discussed on pp. 11-18 of the Plan of Management, incl. photographs.

It is concluded that " the high floral diversity indicates a conservative stocking rate between one and two Dry Sheep Equivalent (DSE)/ ha (with one DSE representing a 55 kg wether). A low stocking rate/ha needs to be kept in place if domestic stock are to be kept for longer periods (e.g. a few months per year) on the property. However if stock are to be used only occasionally throughout the year, i.e. as part of a crash grazing regime where higher densities are used over a short time period, then stocking rates will need to be adjusted accordingly. Stocking rates may also need to be adjusted to take into account additional grazing pressure from kangaroos.

"Getting the right balance in integrating grazing and conservation management will require experience and evolve over time in response to varying factors, and so the best management will need to be dynamic and adaptive. Success in meeting the goals will rely on good on-going monitoring and communication between the landholder and the Trust, and a developed understanding of practical management conditions for grazing of the Conservation Area" (p.11).

The 'Grazing Management Goals' were defined (p.12) as:

"Whilst the Trust and local extension staff will be available to offer recommendations on a suitable grazing regime, the restoration and maintenance of Bunhybee Grasslands will ultimately rely on the experience of the Landholder to judge the timing of moving and excluding stock at the right time to keep the native ground cover in good condition.

"Factors which indicate native ground cover vegetation in a good condition are:

"[Conversely, ]Native ground cover is generally regarded as deteriorated due to over grazing if any of the following factors are observed across the majority of the Conservation Area:

"Native ground cover is generally regarded as deteriorated due to under grazing if monitoring by the Landholder and/or the Trust indicates a marked decrease in the area of inter-tussock spaces combined with a significant increase in cover of tussock grasses (including standing dry matter) across the majority of the paddock" (p. 16). [We interpret this to mean that the height of native grasses (e.g. wallaby grass 20cm, kangaroo grass 50cm) is not an indicator of deterioration, whereas density is.]

"A rest (spell) over spring/summer allows many/most native species to produce seeds and favours seedling recruitment. Grazing during spring/summer may also favour weed species ... These species quickly colonise bare ground and suppress/displace some native species, particularly the small herbs" (p. 14).

Grazing Management Conditions [5.3(e)] are defined as follows (p. 17):

Grazing Management Recommendations were defined as follows (p. 18):


Local Knowledge Acquired Since the Date of Purchase

We've met and/or had phone conversations with Di Izzard (neighbour to the north incl. the incursion on the NW, who's been there over 10 years and whose deceased husband was from the district), Kitty and Harry Tischler (neighbour to the west, at 'Warragandra', who moved there about 2002) and David and Jeanette O'Connell (immediately to the west of 'Warragandra', 5 generations in the district, and at some stage captain of the local Rural Fire Service).

According to David O'Connell, the 'Parlour Paddock', from about 1960 to 2000, carried sheep (merinos, of course), prettymuch constantly, of the order of 650-700 head. The Parlour Paddock was 403 or 424 ha; so assuming on average 50kg wethers, that's 1.5-1.7 DSE/ha/p.a.

That's consistent with what appears to be the appropriate page at DPI, which rates "good quality native pasture, e.g. wallaby grass", at 1.5–3.0 DSE/ha/pa. For 403 or 424 ha, that's 600-1272 DSE. There is limited access to water throughout the old Parlour Paddock (and even less on the northern segment that is now Bunhybee Grasslands), so the bottom end of the range would appear to have been about right.

Allowance needs to be made for kangaroo-grazing. Although a mob is resident on Bunhybee Peak, and one or two have been on the upper edge of the property most times we've been there, they do not seem to have ventured down to the wetter areas much during 2008.

Allowance may need to ne made for grazing by ferals, in particular pigs. The primary impact appears to have been bare patches arising from them grubbing for roots. This peaked in mid-2008, but seems to have eased off in late 2008.

According to both David O'Connell and Kitty and Harry Tischler, little grazing was conducted at all during the period 2002-07. That is consistent with the state of the fencing in late 2008 prior to the sale, along the road and up against Bunhybee Peak – fencing that cattle would have strolled through – and did.

Cattle appear to have only ever on the property in two periods, briefly in the mid-2000s, followed by the famous 8-12 head early in NCT's time, which strolled through the inadequate fencing and had to be 'rescued' by Lauren van Dyke and moved to Scotsdale [in late 2007? – to be confirmed].

Availability of sheep for agistment is limited, because there are few in the region now (because the returns are so low). The main use of pasture in the district is for cattle these days. However, the dam surrounds are weak, and, with very limited water available, the damage that cattle would do to the dam area would probably be substantial. Di Izzard warns that the UK breeds are more likely to find the gaps in the fences (e.g. on the several wombat tracks), so merinos are preferable.

David O'Connell remarked that the paddocks were a fire-risk. Based on the RFS map, we're at the southern end of Palerang zone; but that's not much use, because it merely tells us that RFS zones are based on Local Government Areas. Looks like 'local knowledge' still beats the Web ...


Implications for Bunhybee

Summarising NCT's thinking as at 2007-08, they had a preference for:

Based on:

what seems appropriate for Bunhybee is a DSE/ha/p.a. of at most 1.

That suggests a carrying capacity of 50 x 50kg wethers, year-round.

For very light crash-grazing for 3-4 weeks, the equivalent might be a mob of 150?

The target time-period is February-April.


Elements of a Strategy for 2009-2010

1. Differentiate Areas

The need for grazing to control grass-growth varies between areas, and grazing in the poorer-quality grasslands could be harmful. So areas need to be distinguished.

The Plan of Management identifies "four Grazing Zones, which are based on the vegetation communities’ management needs (see Map 3). Zone 1 and 2 are Snow Gum Woodland areas which vary in tree and shrub cover across the Conservation Area. Zones 3 and 4 are areas of dry and wet Natural Temperate Grassland" (p.11).

We have in mind to declare Zone 5 - Wet Areas, because they have distinctly different ecologies, have quite different vulnerabilities and probably risks, and need quite different management.

Grass growth is greatest in the wet grassland areas (Zone 4). But we need to check that all areas within Zone 4 are comparable to one another.

It appears to us that the dry grassland (Zone 3) varies a great deal. We need to map the parts with more vigorous grass-growth (and that presumably have better soil and/or are subject to more frequent watering and/or less frequent or intensive kangaroo-grazing).

The Snow Gum Woodland (Zones 1 and 2) is mostly quite sparse. We need to check whether any parts of it warrant grazing at this stage.

We may need to specify for-grazing and not-for-grazing segments.

VegZones.jpg

2. Consider Controlled Burning

It may be that the high-grassgrowth / high-fuel-load areas can be controlled by learning the technique of doing low-temperature acre-sized burns, or inviting the local Rural Fire Service to come and do a practice-run. ("Without grazing or fire, the native ground cover at ‘Bunhybee’ Grasslands may become less diverse" – Plan of Management, p. 14).

An attempt at a systemic explanation of this might be:

Hence:

3. Consider differential controls in different segments

Zone 4 appears to be most at risk of loss of species diversity, because that is where the native grasses are very dense, and forbs appear to have been already squeezed out. (But is this natural anyway?). On the other hand, this area appears not to be a significant fire-risk in the current, reasonable conditions.

The 'lushest' segments of Zone 3 may be both at some risk of loss of species diversity and higher fire-risk.

So a mix of grazing and controlled burning in different segments might be more appropriate than one or the other.

Mowing and patch burning are other possibilities.

4. Investigate means of controlling agisted stock:

5. Investigate the practicalities of agisting stock:


Our Current Intentions

Hold off on grazing in autumn 2009.

Map the areas in which grass-growth is an issue.

Track down David Eddy, who has written a book on the topic, and discuss it with him.

Probably do, or arrange, a small trial controlled burn.

Research fencing and watering, and build and maintain our local contacts, so that grazing can be arranged quickly if we change our minds.

Reference:

Eddy D. (2002) 'Managing Native Grassland: a guide to management for conservation, production and landscape protection' WWF, 2002


This is a page within the Bunhybee Grasslands Web-Site, home-page here, and site-map here

Contact: Linda or Roger

Created: 23 February 2009; Last Amended: 1 March 2009